NAME: Streptococcus agalactiae
SYNONYM OR CROSS REFERENCE: Group B streptococci
CHARACTERISTICS: Gram-positive cocci, ~2.0 µm occurring in pairs and short chains, facultatively anaerobic, beta hemolysis on blood agar
PATHOGENICITY: Associated with diseases of the newborn; 90% of cases have septicemia, 40% have pulmonary involvement, and 30% have meningeal involvement; early onset disease acquired in utero or during passage through the birth canal and can have a case fatality rate of 50%; late onset disease with onset from 1 week to 3 months after birth have a case fatality rate of 20% and are probably acquired from the environment: survivors of meningitis cases can be left with hearing loss, blindness, cerebral palsy, mental retardation and/or epilepsy; adult infections include pneumonia, urinary tract infection, peritonitis, meningitis, endocarditis, osteomyelitis and rarely pharyngitis
EPIDEMIOLOGY: Worldwide; mainly causes diseases in infants <3 months of age with low birth weight and in the elderly; predispositions include diabetes mellitus, cancer, HIV
HOST RANGE: Humans, cattle (mastitis), other animals
INFECTIOUS DOSE: Not known
MODE OF TRANSMISSION: The manner of acquisition varies by age; 10-30% of pregnant women harbor Group B streptococci in the genital tract; approximately 1% of their offspring develop symptomatic infection within 6 days of birth; source of infection in older infants, children and adults are not well established
INCUBATION PERIOD: One to seven days for early onset disease, seven days to months for late onset disease
COMMUNICABILITY: Humans carry organisms in throat and vagina; attempts to eradicate genital tract group B streptococci in women during pregnancy with oral antibiotics only partially successful due to reinfection from rectal carriage of the organism or by reacquisition from culture-positive sexual partners
RESERVOIR: Humans, cattle, horses, dogs, rabbits, guinea pigs, mice
ZOONOSIS: Possibly through direct or indirect contact with infected animals (mostly livestock workers); strains causing disease in humans are usually biochemically, metabolically or serologically different than those causing disease in animals; if animal transmission to humans does occur it is rare and of little significance
VECTORS: None
DRUG SUSCEPTIBILITY: Sensitive to penicillin or ampicillin; some strains penicillin tolerant and require treatment with an aminoglycoside as well
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to many disinfectants - 1% sodium hypochlorite and 70% ethanol, formaldehyde, glutaraldehyde, iodines
PHYSICAL INACTIVATION: Sensitive to moist heat (121° C for at least 15 min) and dry heat (160-170° C for at least 1 hour)
SURVIVAL OUTSIDE HOST: Dust - 20 to 30 days; contaminated cows feces - 21-63 days; litter - 20-30 days; paper contaminated with infected milk 4 days; urine 2-6 days; wood - 11 days
SURVEILLANCE: Monitor for symptoms; confirm bacteriologically
FIRST AID/TREATMENT: Antibiotic therapy
IMMUNIZATION: None available
PROPHYLAXIS: Administration of penicillin or ampicillin at the onset and throughout labor to women who are colonized with group B and who are at high risk of delivering an infected infant (premature)
LABORATORY-ACQUIRED INFECTIONS: 78 recorded cases of Streptococcus spp. up to 1976
SOURCES/SPECIMENS: Blood, genital specimens, feces, urine, throat swabs and respiratory specimens
PRIMARY HAZARDS: Accidental parenteral inoculation; ingestion: inhalation of infectious aerosols, direct contact
SPECIAL HAZARDS: None
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for all activities involving known or potentially infected clinical materials or culture; animal biosafety level 2 facilities for studies utilizing infected animals
PROTECTIVE CLOTHING: Laboratory coat; gloves when contact with infectious materials in unavoidable
OTHER PRECAUTIONS: None
SPILLS: Allow aerosols to settle; wearing protective clothing, gently cover spill with absorbent paper towel and apply 1% sodium hypochlorite, starting at perimeter and working towards the centre; allow sufficient contact time (30 min) before clean up
DISPOSAL: Decontaminate before disposal; steam sterilization, chemical disinfection, incineration
STORAGE: In sealed containers that are appropriately labelled
Date prepared: April, 2001
Prepared by: Office of Laboratory Security, PHAC
Although the information, opinions and recommendations contained in this Material Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Copyright ©
Health Canada, 2001
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